With recent developments in electronics, various kinds of electrical and electronic machines and apparatus are being manufactured in large quantities. In parts factories and assembling factories for producing such machines, clean rooms are being employed increasingly. If electrostatic charges are generated in materials inside the clean rooms, the charges should be immediately leaked to prevent the clean rooms from being electrically charged. For this purpose, clean rooms are generally made electroconductive by providing an electroconductive coating or the like on the surfaces of wall and ceiling materials, and by filling flooring materials with electroconductive fillers. Due to such walls, ceiling, and flooring, the electronic machines and parts in a clean room are prevented from suffering burning damages due to the discharge of electrostatic charges generated in the inside of the clean room, and dust particles are prevented from adhering to the inside of the room and lowering the cleanness in the room.
Joints in such wall, flooring, and ceiling materials are caulked with silicone sealants. As such sealants, silicone sealants having electroconductivity have come into use because general-purpose silicone sealants show insulation properties and are easily charged to cause dust particles to adhere to the joints.
However, since wall and ceiling materials have been covered with an electroconductive coating (for example, SEKISUI ASVEIL SA-1000 series; trade name; manufactured by Sekisui Chemical Co., Ltd., Japan) as described above and flooring materials contain special electroconductive fillers in large amount, the silicone sealants inherently show poor adhesion to these antistatic materials. In addition, since the electroconductive silicone sealants also contain a large proportion of an electroconductive filler such as carbon, their adhesion to joint portions of the antistatic materials is poor. Hence, satisfactory caulking of the joints with electroconductive silicone sealants has not been achieved.